College of Information and Control Engineering, China University of Petroleum, Qingdao, 266580, Shandong, People's Republic of China.
Sci Rep. 2021 Nov 25;11(1):22947. doi: 10.1038/s41598-021-02291-2.
Applied Current Thermoacoustic Imaging (ACTAI) is a new imaging method which combines electromagnetic excitation with ultrasound imaging, and takes ultrasonic signal as medium and biological tissue conductivity as detection target. Taking the high contrast advantage of Electrical Impedance Tomography (EIT) and high resolution advantage of ultrasound imaging, ACTAI has broad application prospects in the field of biomedical imaging. Although ACTAI has high excitation efficiency and strong detectable Signal-to-Noise Ratio, yet while under low frequency electromagnetic excitation, it is still a big challenge to reconstruct a high-resolution image of target conductivity. This paper proposes a new method for reconstructing conductivity based on Generative Adversarial Network, and it consists of three main steps: firstly, use Wiener filtering deconvolution to restore the electrical signal output by the ultrasonic probe to a real acoustic signal. Then obtain the initial acoustic source image with filtered backprojection technology. Finally, match the conductivity image with the initial sound source image, which are used as training samples for generating the adversarial network to establish a deep learning model for conductivity reconstruction. After theoretical analysis and simulation research, it is found that by introducing machine learning, the new method can dig out the inverse problem solving model contained in the data, which further reconstruct a high-resolution conductivity image and has strong anti-interference characteristics. The new method provides a new way to solve the problem of conductivity reconstruction in Applied Current Thermoacoustic Imaging.
应用电流热声成像(ACTAI)是一种将电磁激励与超声成像相结合的新型成像方法,以超声信号为媒介,以生物组织电导率为检测目标。ACTAI 结合了电阻抗断层成像(EIT)的高对比度优势和超声成像的高分辨率优势,在生物医学成像领域具有广阔的应用前景。虽然 ACTAI 具有高激励效率和强可检测信噪比,但在低频电磁激励下,仍然难以重建目标电导率的高分辨率图像。本文提出了一种基于生成对抗网络的电导率重建新方法,主要包括三个步骤:首先,使用维纳滤波反卷积将超声探头输出的电信号恢复为真实的声信号。然后,利用滤波反投影技术得到初始声源图像。最后,将电导率图像与初始声源图像进行匹配,作为生成对抗网络的训练样本,建立电导率重建的深度学习模型。通过理论分析和仿真研究发现,通过引入机器学习,该方法可以挖掘出数据中包含的逆问题求解模型,进一步重建出高分辨率的电导率图像,且具有较强的抗干扰特性。该方法为解决应用电流热声成像中的电导率重建问题提供了新的途径。